VIDEO: Clark County Fire Department crews are responding to a structure fire near the Las Vegas Strip Monday morning. The fire is at an office building at 3900 Paradise Road. CCFD Deputy Fire Chief Jeff Buchanan said the fire broke out at 3 a.m. at the two-story commercial structure. Buchanan said they weren't aware of anyone inside the building and officials don't know the origin of the fire. Buchanan said there was still fire in the north and south ends of the building and the roof of the building collapsed in. Just before 8 a.m., fire officials said they still hadn't accessed the interior of the building and were working to control the fire on the exterior. Officials closed Paradise in both directions from Corporate Drive to Twain Avenue while fighting the fire. Smoke from the fire was causing low visibility in the area.